No matter how hard Russia and its Syrian allies try to deny their involvement in the chemical weapons attack on Idlib, all the available intelligence shows they were directly responsible for committing a war crime.
While categorical evidence is always hard to acquire in an active warzone like Syria, intelligence officials in the US and Britain believe there is already sufficient material available to blame the atrocity directly on the Assad regime and its Russian protectors. A regime warplane was identified operating in the area at the time the attack took place.
Moreover, the aircraft was operating in air space controlled by the Russian military, which has been instrumental in turning the tide of the Syrian conflict in Bashar al-Assad's favour in recent months.
By the time the truth is finally established, the international agenda will have moved on, and the likelihood of retaliatory action being taken will be diminished.
The Assad regime will also have drawn encouragement from former US President Barack Obama's failure to follow through on his threat to launch military action after it carried out another chemical weapons attack on its own citizens on the outskirts of Damascus in 2013.